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  6. LTC3838-2

Data Sheet
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JP
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Overview

Features and Benefits

  • Wide VIN Range: 4.5V to 38V
  • VOUT1: 0.6V to 5.5V, ±0.67% Output Regulation Accuracy, with Internal 0.6V VREFERENCE
  • VOUT2: 0.4V to 5.5V, ±4mV Regulation Accuracy, with Differential External VREFERENCE Sensing
  • Differential Remote Output Sensing; Up to ±500mV (VOUT1) and ±200mV (VOUT2) Ground Deviations
  • Fast Load Transient Response Without Clock Delay
  • Detect Transient Release (DTR) Reduces VOUT Overshoot
  • Frequency Programmable from 200kHz to 2MHz, Synchronizable to External Clock
  • tON(MIN) = 30ns, tOFF(MIN) = 90ns
  • RSENSE or Inductor DCR Current Sensing
  • Overvoltage Protection and Current Limit Foldback
  • Power Good Output Voltage Monitor
  • Thermally Enhanced 38-Pin (5mm × 7mm) QFN Package

Product Details

The LTC3838-2 is a dual-channel, PolyPhase® synchronous step-down DC/DC switching regulator controller. Two independent channels drive all N-channel power MOSFETs. The two channels can also be combined into a multiphase single output configuration with external reference.

The controlled on-time, valley current mode control architecture allows for not only fast response to transients without a clock delay, but also constant frequency switching at a steady-load condition. Its proprietary load-release transient detection feature (DTR) significantly reduces overshoot at low output voltages.

The switching frequency can be programmed from 200kHz to 2MHz with an external resistor, and can be synchronized to an external clock. Very low tON and tOFF times allow for near 0% and near 100% duty cycles, respectively. Voltage tracking soft start-up and multiple safety features are provided.

See below for a comparison of LTC3838, LTC3838-1 and LTC3838-2.

Part Number Description
LTC3838   ±0.67% Differential Output Voltage Accuracy Over Temperature on Channel 1, ±1% Output Regulation on Channel 2, Separate Per Channel 30mV to 100mV Current Sense Range Controls
LTC3838-1   ±0.67% Differential Output Voltage Accuracy Over Temperature on Both Channel 1 and Channel 2, Single Pin 30mV/60mV Current Sense Range Controls
LTC3838-2   ±0.67% Differential Output Voltage Accuracy With Internal Reference on Channel 1, ±4mV Differential with External Reference Voltage on Channel 2, Fixed 30mV Current Sense Range

Applications

  • Power for ASICs with Dynamic Voltage Scaling
  • Low Voltage, High Current, High Step-Down Ratio Converters That Demand Tight Transient Regulation

Product Categories

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Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.

Evaluation Kits (1)

Documentation & Resources

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  • Data Sheets (1)
  • Reliability Data (1)
  • Application Notes (1)
  • User Guides (1)
  • Technical Articles (1)
    • Document Type

    Tools & Simulations

    LTspice

    LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

    To launch ready-to-run LTspice demonstration circuits for this part:

    Step 1: Download and install LTspice on your computer.

    Step 2: Click on the link in the section below to download a demonstration circuit.

    Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.

    LTspice

    LTspice Simulations

    LTC3838-2 Demo Circuit - High Current, Dual Output Synchronous Buck Converter (4.5-14V to 1.5V & 1.2V @ 20A)
    LTC3838-2 Demo Circuit - High Efficiency Step-Down DC/DC Converter with Inductor DCR Current Sensing (4.5-14V to 0.4V-2.5V @ 50A)

    Models for the following parts are available in LTspice:

    LTC3838
    LTC3838-1
    LTC3838-2

    LTpowerCAD

    LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.

    LTPowerCAD

    Design tools for the following parts are available in LTpowerCAD:

    LTC3838
    LTC3838DC1626A-ADCRSENSE
    LTC3838DC1626A-BRSENSE
    LTC3838DC1801A-BDEMOBOARDRSENSE

    Product Recommendations

    LTC3838-2 Companion Parts

    Recommended Related Parts

    Design Resources

    ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.

    Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
    LTC3838EUHF-2#PBF Material Declaration Reliability Data 38-Lead QFN (5mm x 7mm w/ EP)
    LTC3838EUHF-2#TRPBF Material Declaration Reliability Data 38-Lead QFN (5mm x 7mm w/ EP)
    LTC3838IUHF-2#PBF Material Declaration Reliability Data 38-Lead QFN (5mm x 7mm w/ EP)
    LTC3838IUHF-2#TRPBF Material Declaration Reliability Data 38-Lead QFN (5mm x 7mm w/ EP)
    Wafer Fabrication Data R526 Reliability Data

    Support & Discussions

    LTC3838-2 Contact ADI Technical Support »
    LTC3838-2 Ask your question »
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